全文获取类型
收费全文 | 143篇 |
免费 | 7篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 28篇 |
金属工艺 | 12篇 |
机械仪表 | 6篇 |
建筑科学 | 4篇 |
矿业工程 | 1篇 |
能源动力 | 5篇 |
轻工业 | 8篇 |
水利工程 | 1篇 |
无线电 | 14篇 |
一般工业技术 | 25篇 |
冶金工业 | 9篇 |
原子能技术 | 3篇 |
自动化技术 | 35篇 |
出版年
2023年 | 3篇 |
2022年 | 1篇 |
2021年 | 10篇 |
2020年 | 5篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 8篇 |
2013年 | 6篇 |
2012年 | 8篇 |
2011年 | 12篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 9篇 |
2007年 | 7篇 |
2006年 | 7篇 |
2005年 | 4篇 |
2004年 | 8篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1981年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有151条查询结果,搜索用时 218 毫秒
1.
Jean-Louis Iehl Rodolphe Grac Luc le Gratiet Véronique Bardinal Rainer Buhleier Elena Bedel-Pereira Chantal Fontaine Michel Pugnet Jacques-Henry Collet 《电信纪事》1997,52(11-12):627-637
We study the transient gratings photogenerated in the picosecond regime in three families of structures, namely : - structures of thickness in the order of one micron, including quantum wells (GaAs/GaAlAs, CdTe/ CdZnTe). A transmission modulation due to the electric field has been observed. We show that, in accordance with our calculations, this modulation is screened faster than 10 ps at a fluence of a few µJ/cm2. - A structure including GalnAs/GalnAsP MQWS in a cavity. This structure shows a top diffraction efficiency of 2.5 × 10-2 at 1.55 µm for an energy of excitation in the order of 100 µJ/cm2. The diffraction efficiency exhibits several oscillations due to Fabry-Pårot effects. By introducing cavity effects in our model, we show that the diffraction efficiency is amplified by more than a factor 2 with respect to the no-cavity case. Calculations show that the diffraction efficiency may reach 6 × 10-2 around 1.625 µm, for a front mirror reflectivity of 90 %. - Structures including bulk GaAs microcavities. The risetime is lower or in the order of 1 ps while the diffraction efficiency attains 1 %, with an average power of 4 mW (i.e. an energy of 2 µJ/cm2/pulse), compatible with a commutation of packets at 80 MHz. 相似文献
2.
Guy-Bart Stan Rodolphe Sepulchre 《Automatic Control, IEEE Transactions on》2007,52(2):256-270
This paper employs dissipativity theory for the global analysis of limit cycles in particular dynamical systems of possibly high dimension. Oscillators are regarded as open systems that satisfy a particular dissipation inequality. It is shown that this characterization has implications for the global stability analysis of limit cycle oscillations: i) in isolated oscillators, ii) in interconnections of oscillators, and iii) for the global synchrony analysis in interconnections of identical oscillators 相似文献
3.
Internal friction has been measured by torsion at 1 Hz during tensile tests performed on glassy polycarbonate at room-temperature. Steady-state flow and transient effects have been studied during continuous tensile tests and strain-rate changes. During steady-state, internal friction and flow-stress vary in a similar way with strain-rate. But during transients, internal friction varies continuously while flow-stress passes through a maximum (or a minimum). These results are interpreted assuming that non-elastic deformation of glassy polymers requires some microscopic discontinuous processes such as motion of defects. Two parameters are considered: the velocity v and the density ρ of mobile defects. Assuming that the former is directly related to the flow stress, it has been shown that internal friction is related to the density of mobile defects ρ. This feature is used to interpret the different stages of a tensile test curve. Activation volumes for both velocity and density of mobile defects are calculated from experimental data. 相似文献
4.
Derek A. Paley Naomi Ehrich Leonard Rodolphe Sepulchre 《Systems & Control Letters》2008,57(3):209-215
We provide a cooperative control algorithm to stabilize symmetric formations to motion around closed curves suitable for mobile sensor networks. This work extends previous results for stabilization of symmetric circular formations. We study a planar particle model with decentralized steering control subject to limited communication. Because of their unique spectral properties, the Laplacian matrices of circulant graphs play a key role. We illustrate the result for a skewed superellipse, which is a type of curve that includes circles, ellipses, and rounded parallelograms. 相似文献
5.
We explore in this paper the relation between activities, communication channels and media, and common ground building in
global teams. We define re-representation as a sequence of representations of the same concept using different communication
channels and media. We identified the re-representation technique to build common ground that is used by team members during multimodal and multimedia communicative events in cross-disciplinary,
geographically distributed settings. Our hypotheses are as follows: (1) Significant sources of information behind decisions
and request for actions are embedded within the fabric of communicative events in which participants use both informal and
formal media to express their ideas. Capturing these information sources can facilitate common ground building and accelerate
the execution of action requests. (2) Re-representations of concepts, i.e., sequences of representations using diverse media
and communication channels, mediate and accelerate common ground building. (3) The use of intra- or interdisciplinary re-representations
correlates with high team performance, i.e., effective team process and high product quality. We used AEC Global Teamwork
course offered in 2008–2009 as the testbed for our study to validate our hypothesis. 相似文献
6.
This paper presents the retrieval method L-APOM which aims at characterizing the microphysical and optical properties of aerosol plumes from hyperspectral images with high spatial resolution. The inversion process is divided into three steps: estimation of the ground reflectance below the plume, characterization of the standard atmosphere (gases and background aerosols) and estimation of the plume aerosols properties. As using spectral information only is not sufficient to insure uniqueness of solutions, original constraints are added by assuming slow spatial variations of particles properties within the plume. The whole inversion process is validated on a large set of simulated images and reveals to remain accurate even in the worst cases of noise: relative estimation errors of aerosol properties remain between 10% and 20% in most cases. L-APOM is applied on a real AVIRIS hyperspectral image of a biomass burning plume for which in situ measurements are available. Retrieved properties appear globally consistent with measurements. 相似文献
7.
Éric Lunaud Ngoupé Clément Parisot Sylvan Stoesel Petko Valtchev Roger Villemaire Omar Cherkaoui Pierre Boucher Sylvain Hallé 《Journal of Network and Systems Management》2017,25(1):180-209
Configuration Logic (CL) is a formal language that allows a network engineer to express constraints in terms of the actual parameters found in the configuration of network devices. We present an efficient algorithm that can automatically check a pool of devices for conformance to a set of CL constraints; moreover, this algorithm can point to the part of the configuration responsible for the error when a constraint is violated. Contrary to other validation approaches that require dumping the configuration of the whole network to a central location in order to be verified, we also present an algorithm that analyzes the correct formulas and greatly helps reduce the amount of data that need to be transferred to that central location, pushing as much of the evaluation of the formula locally on each device. The procedure is also backwards-compatible, in such a way that a device that does not (or only partially) supports a local evaluation may simply return a subset or all of its configuration. These capabilities have been integrated into a network management tool called ValidMaker. 相似文献
8.
Output synchronization of a network of heterogeneous linear state–space models under time-varying and directed interconnection structures is investigated. It is shown that, assuming stabilizability and detectability of the individual systems and imposing very mild connectedness assumptions on the interconnection structure, an internal model requirement is necessary and sufficient for synchronizability of the network to polynomially bounded trajectories. The resulting dynamic feedback couplings can be interpreted as a generalization of existing methods for identical linear systems. 相似文献
9.
Gels formed by altering α-doped (Np, Pu, Am) SON68 glass at 300 °C were leached during 1 year at 44 cm−1 and 50 °C under oxidizing conditions (Eh/NHE ≈ +150 mV) and under reducing conditions (Eh/NHE ≈ −250 mV). After 3 days of leaching the gel dissolution was highly incongruent. The gel dissolution rate calculated from the silicon concentrations was 4.4 × 10−5 g m−2 d−1, except for the Am-doped gel, for which the rate was two times higher. During leaching, Np is weakly retained in the gel (35% under oxidizing conditions and 50% under reducing conditions) whereas Pu and Am are strongly retained (over 90%). The three lanthanides La, Ce, and Nd exhibit exactly the same leaching behavior, but different from that of actinides. Speciation and complexation calculations for neodymium showed that its solubility could be controlled by Nd(OH)3 for periods beyond 3 months. Conversely, no simple chemical compound appears to control the solubility of the actinides. 相似文献
10.
Rodolphe Bolot Sihao Deng Zhenhua Cai Hanlin Liao Ghislain Montavon 《Journal of Thermal Spray Technology》2014,23(3):296-303
Offline robot trajectory generation is now often used for thermal spray applications, especially for complex design parts, requiring enhanced trajectories. This technique allows decreasing the downtime of the thermal spray cell and insures the generation of optimized trajectories. Heat transfers caused by thermal spray increase the workpiece temperature during the coating application. This temperature acts directly on the resulting thermal stresses after cooling of the part down to the ambient temperature. In this study, a coupling was developed between the robot trajectory and computation of the thermal history of the workpiece during the spray operation. The method is based on the storage of the real robot trajectory (i.e., accurate in time) in a text file, and reading of this file with a C programming performed with ANSYS/FLUENT commercial code which allows computing the displacement of the thermal sources according to the trajectory and solving the transient heat conservation equation during the torch displacement. The contributions of the impinging plasma jet and the molten particle jet are taken into account in the model. 相似文献